Self retractable sound plug

ABSTRACT

A self retractable sound plug for use in association with a transducer, generally located in the arm of an airpassenger seat.

Unite States Patent Machado 1March 20, 1973 54 SELF RETRACTABLE SOUND PLUG 4 3,444,954 5/1969 Scanlon ..l81/24 Inventor: p Machado Anleboro Mass. 3,547,2l9 12/1970 Bothos ..l8l/3l R [73] Assignee: Avid Corporation, East Providence, Primary Examiner-Stephen J. Tomsky R.l. Attorney-William Frederick Werner [22] Filed: April 20, 1972 [57] ABSTRACT [21] Appl 245820 A self retractable sound plug for use in association with a transducer, generally located in the arm of an [52] [1.5. CI. ..l8l/3l R, 181/24 airpassenger seat. [51] lint. Cl ..G10k 13/00, H04r 1/28, A6lb 7/02 [58] Field of Search ..l8l/31 R,3l B, 24

[56] References Cited 2 Claims, 8 Drawing Figures UNITED STATES PATENTS 3,294,195 12/1966 Flygstad ..l8l/24 II I 5 l0 PATENTEUIARZO I973 HG. I.

SELF RETRACTABLE SOUND PLUG The present invention relates to retractable and reusable sound plugs which are self retractable and reset into usable condition by means of a special tool.

An object of the present invention is to provide a self retractable sound plug upon the end of the sound tubes of a stethoscope for use by airplane passengers.

In the past an airplane passenger received a sound tube head set or stethoscope upon boarding the airplane for a fee. The passenger was free to plug the head set tube jacks into a transducer located in the arm of the passenger seat. Since the passenger paid for the stethoscope, he took possession and carried the stethoscope off the plane. The next time he boarded the plane he refused to purchase a stethoscope because he brought his own along. To avoid this loss of revenue, the present invention was created whereby when the passenger withdraws the stethoscope jack or sound plug, the plug is automatically withdrawn within the casing so that it cannot be reused without being reset by means of a special resetting tool.

It is therefore an object of the present invention to provide a sound plug which is rendered inoperative after use but which may be reset after each use for unlimited operation.

Other objects of the present invention will become apparent in part and be pointed out in part in the following specification and claims.

Like reference numerals refer to like parts in the following drawings in which:

FIG. 1 is a side elevational view of the new and improved self retractable sound plug.

FIG. 2 is a perspective view of the special tool used to reset the self retractable sound plug.

FIG. 3 is a top plan view of FIG. 1.

FIG. 4 is a vertical cross sectional view taken on line 44 of FIG. 3 showing the sound plug in operative or extended position.

FIG. 5 is a view similar to FIG. 4 showing the sound plug in inoperative or retracted position.

FIG. 6 is a vertical cross sectional view taken on line 66 of FIG. 3 showing the sound plug in operative or extended position.

FIG. 7 is a view similar to FIG. 6 showing the sound plug in inoperative or retracted position.

FIG. 8 is a perspective view of the spring retaining clip.

Referring to the drawings, wherein is illustrated, a self retractable sound plug, generally indicated by reference numeral 10, includes a casing 11, a cap 12, a sound plug 13, a spring retaining clip 14 and coil springs 15, 16.

Casing 11 provides a chamber 17 open at one end. At the open end the inner casing wall is provided with ledges 18, 19 and a cap surface 20. At the other end casing 11 is provided with two ports 21, 22 and two shelves 23, 24.

Cap 12 is provided with two sound tube openings 25, 26 which terminate respectively, in cavities 27, 28, and with two prong receiving passageways 29, 30.

Sound plug 13 is provided with a mid-body portion 32 which slidably engages inner wall 33 of casing 11. Two plug extensions 34, 35 project from mid-body portion 32 in one direction and two circular bosses 36, 37 extend from portion 32 in an opposite direction. Midbody portion 32 forms spring seats 38, 39 at the juncture of plug extensions 34, 35. Plug extensions 34, 35 may be provided, respectively, with serrated surfaces 40, 41. Two sound tube passageways 42, 43 are provided; one in circular boss 36, mid-body portion 32 and plug extension 34 and the other in circular boss 37, mod-body portion 32 and plug extension 35. Tube seats 45, 46 are provided, respectively, in sound tube passageways 42, 43.

Spring retaining clip 14 has a base 50 provided with boss clearance orifices 51, 52 and two oppositely located resilient wings 53, 54.

The self retractable sound plug is assembled as follows: Spring retaining clip 50 through clearance orifices 51, 52 passing over, respectively, circular bosses 36, 37 is placed upon platform 56 which is the top surface of mid-body portion 32 with wings 53, 54 projecting upwardly and flared outwardly away from each other at the outer surfaces, see FIG. 6. Base 50 is fastened to platform 56 as by means of cement, welding or chemically attached. Coil springs 15, 16 are placed, respectively, over plug extensions 34, 35. Sound plug 13 is passed throughthe open end of chamber 17 and into chamber 17 with plug extensions 34, 35 passing, respectively, through ports 21, 22 with coil springs interposed between shelves 23, 24, respectively, and spring seats 38, 39, respectively. Cap 12 is passed through the open end of chamber 17 with the side of cap 12 slidably engaging cap surface 20 and with the bottom edge 60 of cap 12 abutting ledges 18, 19. Cap 12 is fastened to casing 11, as by means of cement or chemically attached.

FIGS. 1, 4 and 6 show the sound plug 13 in operative position. FIGS. 5 and 7 show the sound plug 13 in operative position. A transducer T is shown in dot and dash lines in FIG. 1. The sound tubes S of a stethoscope are shown in dot and dash lines in FIGS. 1, 4, 5, 6 and 7 In operation, let it be assumed that the self retractable sound plug 10 is in inoperative position and that it is desired to place the sound plugs 34, 35 in operative position.

The prongs P of the hand tool, generally indicated by reference numeral 75, and shown in FIG. 2, are passed into passageways 29, 30 so that the bevel edges B engage the flared edges F of wings 53, 54, and push the spring retaining clip 50 and mid-body portion 32 downwardly against the tension of coil springs 15, 16

until flared edges F slide under and engage a pair of beveled edges A provided on the bottom surface of cap 12 (see FIGS. 6 and 7). This action places sound plugs 34, 35 in extended or operative position.

The self retractable sound plug 10 may now be inserted into a transducer T and sound tubes S may be inserted into sound tube passageways 42, 43.

The service period having terminated, casing 11 will be manually withdrawn from transducer T. In the process of withdrawing the casing 11 the sound plugs 34, 35 assisted by serrations 40, 41 will frictionally grip the walls of the transducer so that the casing 11 will lift upwardly relative to the sound plugs to thereby compress coil springs 15, 16 and move beveled edges A upwardly away from flared edges F to permit wings 53, 54 to move toward each other, as shown in FIG. 7, whereby, the coil springs 15, 16 forces sound plugs 34, 35 into chamber 17 and inoperative position.

Hand tool 75 is then used to place the sound plugs 34, 35 in operative position, as previously described.

Having shown and described a preferred embodiment of the present invention by way of example, it should be realized that structural changes could be made and other examples given without departing from either the spirit or scope of this invention.

What I claim is:

l. A self retractable sound plug comprising a casing provided with a chamber open at one end and two ports and two shelves at the other end, a cap provided with two sound tube openings which terminate, respectively, in two cavities, and with two prong receiving passageways, said cap located in said chamber at said open end, means fastening said cap to said casing, a sound plug having a mid-body portion with two plug extensions projecting in one direction and two bosses extending in an opposite direction, said sound plug located in said chamber and slidably mounted to said casing for movement within said casing with said two plug extensions located, respectively, in said two ports, and projectable through said ports, a coil spring located around one of said two plug extensions and interposed between one of said two shelves and said mid-body portion, a second coil spring located around the other of said two plug extensions and interposed between the other of said two shelves and said midbody portion, two sound tube passageways located, respectively, one in one of said bosses, mid-body portion and one of said plug extensions, the other in the other of said bosses, mid-body portion and the other of said plug extensions, said two sound tube passageways aligned, respectively, with said two sound tube openings, a spring retaining clip having a base provided with two boss clearance orifices and two oppositely located resilient wings, means fastening said spring retaining clip to said mid-body position, with said two boss clearance orifices located, respectively, around said two bosses, said two oppositely located resilient wings engageable and disengageable with said cap in cooperation with the compression and extension, respectively, of said two coil springs.

2. A self retractable sound plug comprising a casing provided with a chamber open at one end and two ports and two shelves at the other end, a cap provided with two sound tube openings which terminate, respectively, in two cavities, and with two prong receiving passageways and a bottom surface, a pair of beveled edges provided on the bottom surface of said cap, said cap located in said chamber in said open end, means fastening said cap to said casing, a sound plug having a mid-portion with two plug extensions projecting in one direction and two circular bosses extending in an opposite direction, said sound plug located in said chamber and slidably mounted to said casing for movement within said chamber, and with said two plug extensions located, respectively, in said two ports and projecting through said ports in operative position and located within said ports and chamber in inoperative position, two coil springs located, respectively, around said two plug extensions and within said chamber between said two shelves and said mid-body portion, two sound tube passageways located, respectively, one in one of said two circular bosses, mid-body portion and one of said plug extensions, the other of said two sound tube passageways located in the other of said two circular bosses, mid-body portion and the other of said two plug extensions, said two sound tube passageways aligned, respectively, with said two sound tube openings, a spring retaining clip having a base provided with two boss clearance orifices and two oppositely located resilient wings which project upwardly and flare outwardly away from each other at the outer surfaces, means fastening said spring retaining clip to said mid-body portion with said two boss clearance orifices located, respectively, around said two circular bosses, said two oppositely located resilient wing outer surfaces engageable and disengageable, respectively, with said pair of beveled edges in cooperation with the compression and extension, respectively, of said two coil springs and a tool insertable through said two prong receiving passageways. 

1. A self retractable sound plug comprising a casing provided with a chamber open at one end and two ports and two shelves at the other end, a cap provided with two sound tube openings which terminate, respectively, in two cavities, and with two prong receiving passageways, said cap located in said chamber at said open end, means fastening said cap to said casing, a sound plug having a mid-body portion with two plug extensions projecting in one direction and two bosses extending in an opposite direction, said sound plug locaTed in said chamber and slidably mounted to said casing for movement within said casing with said two plug extensions located, respectively, in said two ports, and projectable through said ports, a coil spring located around one of said two plug extensions and interposed between one of said two shelves and said mid-body portion, a second coil spring located around the other of said two plug extensions and interposed between the other of said two shelves and said midbody portion, two sound tube passageways located, respectively, one in one of said bosses, mid-body portion and one of said plug extensions, the other in the other of said bosses, mid-body portion and the other of said plug extensions, said two sound tube passageways aligned, respectively, with said two sound tube openings, a spring retaining clip having a base provided with two boss clearance orifices and two oppositely located resilient wings, means fastening said spring retaining clip to said midbody position, with said two boss clearance orifices located, respectively, around said two bosses, said two oppositely located resilient wings engageable and disengageable with said cap in cooperation with the compression and extension, respectively, of said two coil springs.
 2. A self retractable sound plug comprising a casing provided with a chamber open at one end and two ports and two shelves at the other end, a cap provided with two sound tube openings which terminate, respectively, in two cavities, and with two prong receiving passageways and a bottom surface, a pair of beveled edges provided on the bottom surface of said cap, said cap located in said chamber in said open end, means fastening said cap to said casing, a sound plug having a mid-portion with two plug extensions projecting in one direction and two circular bosses extending in an opposite direction, said sound plug located in said chamber and slidably mounted to said casing for movement within said chamber, and with said two plug extensions located, respectively, in said two ports and projecting through said ports in operative position and located within said ports and chamber in inoperative position, two coil springs located, respectively, around said two plug extensions and within said chamber between said two shelves and said mid-body portion, two sound tube passageways located, respectively, one in one of said two circular bosses, mid-body portion and one of said plug extensions, the other of said two sound tube passageways located in the other of said two circular bosses, mid-body portion and the other of said two plug extensions, said two sound tube passageways aligned, respectively, with said two sound tube openings, a spring retaining clip having a base provided with two boss clearance orifices and two oppositely located resilient wings which project upwardly and flare outwardly away from each other at the outer surfaces, means fastening said spring retaining clip to said mid-body portion with said two boss clearance orifices located, respectively, around said two circular bosses, said two oppositely located resilient wing outer surfaces engageable and disengageable, respectively, with said pair of beveled edges in cooperation with the compression and extension, respectively, of said two coil springs and a tool insertable through said two prong receiving passageways. 